This invention relates to metal-to-metal seals for sealing joints of pipe and the like against leakage and is particularly directed to a bi-directional metal-to-metal seal for sealing such joints against leakage in the event a reversal of flow of the fluid under pressure occurs in the flow path. This invention is also directed to the use of a plurality of such seals as a cluster of seals held in a retainer as an assembly so that the entire assembly of seals may be installed or removed at the same time. The latter assembly is especially useful in flowline connections in the oil and gas industry.
The use of metal-to-metal seals for sealing joints of pipe and the like against leakage of various types is old. See, for example, the fire-resistant metal-to-metal seal as disclosed in the U.S. Pat. No. 4,471,965 to Jennings, et al, and especially those having pressure-responsive lips such as shown in the U.S. Pat. Nos. 2,405,152 to Kitchenmann; 3,455,562 to Burtis; the French Patent No. 1,356,218 of the Cadillac Gage Company; and the U. K. Patent Application No. 2,000,234A of Panigati; all of which were sited in the Jennings, et al, patent.
None of the foregoing seals, however, were effective to seal a flow path in two directions in the event of a reversal of the flow of fluid under pressure in the flow path. Also, none of the patents disclosed a metal-to-metal seal which could be inserted and removed without galling or scoring the sealing surface which the seal engaged, nor do any of the patents disclose an assembly of a cluster of seals which may be installed or removed all at the same time. As it will be apparent to those skilled in the art, the use of such an assembly is particularly advantageous in installing and removing multiple seals used in flowline connectors where a plurality of flowlines (individual pipe lines) terminate at a common point to be connected, usually below the surface of the water in subsea well systems.